I got my bike stolen so my shop owner got me a AM but I'm like 6'2" and need a 21" toptube. the AM was only 20" so some kid bought a new frame and gave his PRO to me so that I could have a little bit longer frame.
The Maderas have no warranty that I know of. Nothing in the box or on their website.
And they are completely round..no flat side to the arms at all.